3

stiffener, so that each component element will behave as a stiffened element, and Is and As are the moments of inertia of the full-section of the stiffener, about its own centroidal axis parallel to the element to be stiffened, and the effective area of the stiffener, respectively. For the stiffener shown in Figure 6.15

6.5.5.2 Serviceability Determination

The effective width, bd, used in determining serviceability is calculated as in Section 6.5.5.1, except that fd is substituted for f.

6.5.6 Uniformly Compressed Elements with Intermediate Stiffeners

The effective width of uniformly compressed elements with intermediate stiffeners can also be determined from the AISI Specification, which includes separate design rules for compression elements with only one intermediate stiffener and compression elements with more than one intermediate stiffener.

6.5.6.1 Uniformly Compressed Elements with One Intermediate Stiffener

The following equations can be used to determine the effective width of the uniformly compressed elements with one intermediate stiffener as shown in Figure 6.16.

6.5.6.1.1 Strength Determination

Ia = 0 (no intermediate stiffener required)

The effective width, b, is calculated in accordance with Equations 6.6 through 6.9 with k determined as follows: